var buf11 = Buffer.from('hello world 你好','utf-8');
console.log(buf11.toString());
var buf22 = Buffer.alloc(buf11.length)
buf11.copy(buf22);
console.log(buf22.toString());
buf11.write('我很好udfkajlkdfjlkasjdfkljaskldfjlkasdjfklasjdlkfa');
console.log(buf11.toString());
console.log(buf22.toString());
